Jantar Mantar, Ujjain - One of the Oldest Observatories of the World

Jantar Mantar or the Observatory, Ujjain was built by Sawai Raja Jai Singh between 1725 and 1730 AD. Since then, it has been an important structure for historical as well as astronomical research and is one of the crucial centres for study even today. The name Jantar Mantar comes from Sanskrit words 'Yantra' and 'Mantra' meaning the magical instrument.

Hindu astrologers and scholars from all over the country came to Ujjain for research and studies based on this Observatory. Developing of Jantar Mantar was in fact one of the many milestones achieved in the 18th century. Now Astronomical studies are still conducted here. In fact, an ephemeris, a journal showing the daily speed and position of the planets, is published annually.

Ujjain’s is an ancient city. In fact, much before the observatory was constructed, the place served as a foremost centre for mathematics and astronomy of India.  One of the earliest description standard time could be found in Surya Siddhanta.

As understood, this architectural masterpiece enjoys an immense significance in the field of astronomy. According to some experts, the Tropic of Cancer passes through the city, which makes the Observatory, Ujjain an important place for geographers as well. The then Maharaja of Gwalior, Madhav Rao Scindia renovated the structure in 1923 AD. Passing through the ravages of time, the place still holds a lot of significance not only in terms of research but also as an amazing spot for tourism.

Quick Facts

•    This architectural marvel is also called the Vedh Shala Observatory
•    It is one of the oldest observatories and the part of the five observatories founded in different Indian cities during 17th century
•    The construction started under the supervision of Maharaja Jai Singh in 1719
•    The primary idea was to help Hindu scholars and astrologers with their research and studies
•    It serves not only as an astronomical structure but also as a popular tourism spot today
•    One of the finest places for stargazers


The sun dial of Jantar Mantar was used to study and analyse the movement of the celestial bodies, and predict the solar events. The instruments are still used for astronomical research. Analysis of planetary movements is published in the leading astronomical journals. The Jantar Mantar showcases India’s scientific aptitude and knowledge.

The Architecture

•  Shankhu Yantra

This architecture is a vertical gnomon (piece of a sundial that casts shadow) on a circular platform and you can calculate the length of the day with this shadow. Lines, and the gnomon’s shadow indicates the equinoxes and solstices as it marks the Bhoomadhya (Equator), Karka rekha (Tropic of Cancer), and Makar rekha (Tropic of Capricorn). A vertical gnomon (Shanku) remains set at the centre of the circular platform which is a horizontal plane. According to this, 22nd June is the longest day of the year, 22nd December is the shortest day of the year, 23rd September and 21st March on each year, have equal days and nights. These lines also stand for the zodiac signs. The shadow of the gnomon helps in determining the Zenith distance of the Sun as well as the angle of elevation. Interestingly, the latitude of the Ujjain is represented through the midday shadow on equinoctial days.  

•  Digansha Yantra

This structure is used to analyse the altitude or distance from the horizon of the planets and stars its azimuth (the angular distance from the east or west measured along the horizon) which can help to find out the various astronomical needs as and when required. Astrologically, this helps to measure which planet is transiting from which nakshatra (celestial house) and also find out the distance from Earth, and hence calculate the impact on horoscopes. The Turiya Yantra has a suspended thread which helps to calculate the altitude on the graduated scale of the quadrant.

•  Samrat Yantra

The Supreme Instrument or the Samrat Yantra or sundial is used to tell the time. This is a 22 feet long instrument and is the signature structure of the Observatory, Ujjain. It has a staircase at an inclination 23 degree and 10 degrees and is the equinoctial sundial of the great Jantar Mantar.

The structure is unique in the sense that upper orbital plane of the two walls beside the steps in the middle of this piece are parallel to the axis of the Earth. With this setting, the pole star becomes visible during the night. Two quadrants are situated in the plane of the celestial equator and are placed to the east and the west side of the wall. The quadrants have on it the hours, minutes and fraction of a minute engraved for proper findings. A long flight of steps in the middle of the instrument casts a shadow on two walls on either side.

•  Nadi Valay Yantra

Built in the plane of the celestial equator, there are two main parts of the structure - northern and southern. The concept is simple - north disc illuminates when the sun is in the northern hemisphere and the reverse for six months each. When there is the shadow peg parallel to the axis of the earth, fixed at the centre of the disc, it is the time of Ujjain. This helps to find out the equinoctial days and also find in which hemisphere is the celestial body placed.

•  Bhitti Yantra

This is the transit instrument and is particularly find in Ujjain’s Vedshala. This is used to calculate the zenith distance of any celestial body with respect to Earth.

•  Planetarium

Inside the Observatory, Ujjain, there is a taramandel (a small planetarium) and holds 20- and 30-minute shows for visitors on planets, constellations, stars and galaxies.

Visiting Hours and Tickets Fee

Visiting time: 9:00AM – 5:00PM
Ticket Fee: Rs.200 for foreigners
Visit Duration: 30 – 60 minutes
Note: Visiting during mid-day is recommended.

How to reach the Observatory, Ujjain

Located at Jayasinghpura, Jantar Mantar or The Observatory is easily accessible through local buses and cabs from any corner of the city.

As you visit the Observatory, Ujjain, you can find guides who fill help you understand the functionalities of each of the structures. The information panels in English can also be of help.


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